672
FXUS62 KRAH 201949
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
349 PM EDT Thu Jun 20 2024

.SYNOPSIS...
Anomalously strong high pressure centered over the Middle Atlantic
will gradually weaken while migrating southwestward into the
Tennessee Valley Friday and into the weekend. A cold front will
approach the region on Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 345 PM Thursday...

The anomalous mid/upper ridge sampled at 598 dam from this morning`s
KPZ and KIAD soundings (slightly weaker than last night but still
quite strong) currently stretches across the northern Mid-Atlantic.
It will drift SW to the TN Valley tonight. At the surface, high
pressure centered east of the Delmarva will slowly drift south to
become centered east of the southern VA/northern NC coast by
tomorrow morning. This pattern will support light easterly low-level
flow shifting more southeasterly tonight. Dew points have again
bottomed out in the upper-50s to lower-60s this afternoon, keeping
heat indices close to the air temperatures which are in the
the mid-80s to lower-90s. Once again an extensive deck of scattered
to broken mid-level cumulus has already developed across the region,
but it remains flat under a strong subsidence inversion. So a
complete lack of instability will preclude any convective
development for the rest of the afternoon and evening. Lows tonight
may be a touch milder with slightly rising thicknesses, in the mid-
to-upper-60s. Patchy fog/mist again can`t be ruled out in the
Coastal Plain late tonight/early tomorrow morning.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 340 PM Thursday...

The slightly weaker but still strong 596 dam mid-level anticyclone
will continue to slowly weaken and drift further SE on Friday,
reaching the Deep South on Friday night. At the surface, high
pressure east of NC will continue to nose westward and move south
closer to Bermuda. With the low-level flow switching to a S/SE
direction, 1000-850 mb thicknesses will slightly rise by 5-10 m
compared to today, supporting high temperatures mainly in the lower-
90s across central NC. Dew points will also be slightly higher but
with good mixing should still bottom out in the lower-to-mid-60s.
However, guidance shows some upper-60s dew points and 500-1000 J/kg
of CAPE creeping into the far SE in the afternoon. This is also
where a few CAMS (including the NSSL, ARW and NAMNest) depict a few
showers and storms potentially making it from the coast. So added a
slight chance of showers and storms just over southern Sampson
County from 18z-00z. Any convection would quickly die off after
sunset, with milder lows in the upper-60s to 70 as higher dew points
begin to overspread the whole area.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 323 AM Thursday...

..Dangerously Hot Temperatures Expected this Weekend and into Early
Next Week...

As the mid/upper level ridge continues to stay atop the OH and TN
valleys, hot dry weather will be the main story for the weekend.  By
late Sunday an upper level trough will be moving across the OH and
TN valley into the Mid-Atlantic bringing a surge of upper level
moisture through Monday. Another trough is expected to move across
the region again late week before upper level ridging settles in for
late week.

At the surface high pressure combined with south/southwesterly flow
will result in warm humid conditions over the weekend. Temperatures
are expected to be in the mid to upper 90s across the region. Heat
indices ranging from 100-105 F can be expected across the Triangle
region Saturday with more widespread heat indices of 104 -108 F
Sunday across the Triangle, Sandhills and Coastal Plain regions.
While a lee trough develops east of the Appalachian mountains this
is expected to bring the Triad a bit of relief starting Sunday night
and the rest of the area Monday. For now have PoPs beginning in the
NW late Sunday night before spreading east across the region Monday.
There could be a lull in overall precipitation during the day Monday
but expect showers and storms to regain energy by the afternoon
hours. As a cold front swings down from the north Tuesday, a few
lingering isolated showers and storms could be possible again on
Tuesday, as well as small relief from the heat. Highs on Tuesday
will range from low to mid 90s, with heat indices in the mid to
upper 90s.

The heat is expected to return Wednesday and Thursday with highs in
the mid to upper 90s. Humidity will also slowly be returning ahead
of another frontal passage  thus areas along and east of US-1 could
experience heat indices of 100 -104 F. Long range models suggest
another front could impact the area with another round of
precipitation late week but the timing is uncertain. For now just
have afternoon PoPs across the region each afternoon.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
As of 200 PM Thursday...

Dry weather and VFR conditions will largely prevail through the
period. The one exception is possible IFR or MVFR visibilities from
fog/mist in the Coastal Plain again (including at RWI) late
tonight/early tomorrow morning, as occurred the last couple days.
Otherwise just scattered to broken mid-level cumulus will continue
this afternoon. Offshore high pressure will bring light easterly
winds that shift more southeasterly tomorrow.

Outlook: VFR and dry conditions are expected to persist through
Saturday. An approach of a northern stream trough and attendant cold
front into the region will support a slight chance of showers and
storms and related sub-VFR restrictions on Sunday, with better
coverage on Monday. Isolated showers and storms may linger in the
south and east on Tuesday.

&&

.CLIMATE...

Record High Temperatures:

June 22:
KRDU: 100/2022
KFAY: 101/2022

June 23:
KRDU: 100/1986
KFAY: 102/1981

June 24:
KRDU: 99/2010
KFAY: 102/1914

June 25:
KRDU: 100/1952
KFAY: 102/1914


Record High Minimum Temperatures:

June 22:
KGSO: 75/1981
KRDU: 78/1933

June 23:
KGSO: 74/2015
KRDU: 77/1890
KFAY: 77/2017

June 24:
KGSO: 76/2015
KRDU: 76/1888
KFAY: 79/2010

June 25:
KGSO: 75/2015
KRDU: 77/2010
KFAY: 75/1952

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...cbl
NEAR TERM...Danco
SHORT TERM...Danco
LONG TERM...ca
AVIATION...Danco/cbl
CLIMATE...RAH